The present invention relates generally to gas turbine engine combustor mixers and more particularly to a combustor mixer having a plasma generating fuel nozzle.
Fuel and air are mixed and burned in combustors of gas turbine engines to heat flowpath gases. The combustors include an outer liner and an inner liner defining an annular combustion chamber in which the fuel and air are mixed and burned. A dome mounted at the upstream end of the combustion chamber includes mixers for mixing fuel and air. Ignitors mounted downstream from the mixers ignite the mixture so it burns in the combustion chamber.
Governmental agencies and industry organizations regulate the emission of nitrogen oxides (NOx) from gas turbine engines. These emissions are formed in the combustors due in part to high flame temperatures caused by high fuel-air ratios and/or poor fuel-air mixing. Efforts to reduce NOx emissions by reducing fuel-air ratios have led to lean blowout and acoustical vibration problems. Thus, there is a need in the industry for combustors having improved mixing and reduced emissions without blowout and acoustical vibrations.
Among the several features of the present invention may be noted the provision of a mixer assembly for use in a combustion chamber of a gas turbine engine. The mixer assembly comprises a mixer housing having a hollow interior, an inlet for permitting air to flow into the hollow interior and an outlet for permitting air to flow from the hollow interior to the combustion chamber. The housing delivers a mixture of fuel and air through the outlet to the combustion chamber for burning to heat air passing through the combustion chamber. Further, the mixer assembly includes a fuel nozzle assembly mounted in the housing having a fuel passage adapted for connection to a fuel supply for supplying the passage with fuel. The passage extends to an outlet port for delivering fuel from the passage to the hollow interior of the mixer housing to mix the fuel with air passing through the mixer housing. The nozzle assembly includes a plasma generator for generating at least one of a dissociated fuel and an ionized fuel from the fuel delivered through the nozzle outlet port to the hollow interior of the housing.
In another aspect, the mixer assembly comprises a mixer housing and a swirler assembly mounted in the mixer housing. The swirler assembly has a plurality of vanes adapted for swirling air passing through the hollow interior of the housing. Further the mixer assembly includes a fuel nozzle assembly having a plasma generator for generating at least one of a dissociated fuel and an ionized fuel from the fuel delivered through the nozzle outlet port to the hollow interior of the housing.
Other features of the present invention will be in part apparent and in part pointed out hereinafter.